Electrically operating sound recorder and reproducer



July 7, 1931. c. HUENLICH 1,312,957

vELECIRICALLY OPERATING SOUND RECORDER AND REPRODUCER Filed Nov. 5. 1928 2 Sheets-Sheet 1 Fig. 1

4 INVENTOR C -A4. M BY I A ORNEY July 7, 1931. c. HUENLICH 1,312,957

ELECTRICALLY OPERATING SOUND RECORDER AND REPRODUCER Filed Nov. 3. 1928 v 2 Sheets-Sheet 2 INVENTOR TORNEY Patented July 7, 1931 oneness HUENLICH, or BLOOMFIEL-D, NEW JERSEY, IncoaroR-Arnn or'wnsr ORANGE, NEW JERSEY, A

ASSIGNOR TO THOMAS A. EDISON, CORPORATION or NEW JERSEY ELECTRIGA LLY OPERATING SOUND RECORDER AND REPRODUCER Application filed November 3, 1928. Serial No. 316,896.

This invention relates to an electrically operating sound recorder and reproducer, and more particularly toapparatus for electrically recording and reproducing sounds on records of the type used on dictating machines, in which the 'stylus engraves a socalled hill and dale groove on a cylindrical record.

Itis an object'of the present invention to provide electrical recording and reproducing apparatus which is- Simple to construct, rugged and" reliable in operation and which willengrave a record of high quality, that p is to say, one in which the distortion introduced by the recording or reproducing apparatus itself is minimized. I

' It is still a further object of this invention to provide apparatus of the class described which is asvlittle as possible affected by the presence of stray electrical disturbances in the neighborhood, such, for example, as the disturbances due to the electrical current op erating the motor which drivesthe mandrel on which the record cylinder is mounted.

Still other objects and advantages of my invention will be apparent from the specification.

' The features of novelty which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its fundamental principles and as to its partic-' ular embodiments, will best be understood by reference to thespecification and accompanying drawings, in which Figure 1 is a front elevation of a sound recorder according to my invention;

Figure 2 is a side elevation thereof; Figure 3is a bottom plan view thereof;

Figured is a detail perspective view of the link; f

Figure 5 is a front elevation of a reproducer according to my invention; Figures 6 and 7 are, respectively, side elevation and bottom plan views of the reproducer shown in Figure 5, and

Figure 8 is a top plan view of the floating support forthe reproducer lever.

' In accordance with my invention, I pro vide aframe arranged to be attached to the dictating machine in such a manner as to permit a stylus to operate on the usual form of cylindrical record. Above the frame there is adjustably mounted a magnet support carrying an electromagnetic driving motor or pick-up. Below the frame there is provided a support pivoted at one side to the frame, which I term a floating support. On one side of the supporting frame there is mounted a lever pivoted intermediate its ends for oscillation, on one end of'which there is attached a suitable cutting or reproducing stylus.

The electromagnetic driving motor preferably consists of a balanced armature arrangement, in which there is provided an armature of magnetic material resiliently biased to neutral position and positively vi-' brated in either direction. A rigid link is provided between the end of the armature and the end of the lever opposite the stylus. The oscillating lever may be mounted upon insulation, which may also be mechanical damping material, and the armature may be supported upon insulating material, which may be mechanical damping material, in such a manner that the entire vibrating sys tem is electrically and mechanically insulatcd from who frame, for a purpose which will be described more in detail.

Referring now more particularly to Figures l and 2, 1 designates the frame or base plate, by means of which the apparatus may be positioned upon the usual type of dictating machine. The magnet support comprises a plate having a portion 4 arranged to be clamped to the base plate 1 by means of suitable clamping bolts 5, and the holes in plates 1 and 4:, or either of them, are so'arranged as to permit of adjustment of the magnet support on the base plate 1. In the preferred form, I provide slots in the plate 4. The plate 4 is provided with a vertical extension 7 on which there is mounted the electromagnetic driving motor designated generically as 8, and held in position by means of suitable clamping bolts 9 and 10 passing through the motor assembly and the support 7. The motor assembly may be spaced from and insulated from the support 7 by the use of an interposed spacer of metal 11 and a strip of insulating material, such as bakelite or fibre 11a. The driving motor itself comprises a .U shaped permanent magnet 15, and a pole piece assembly v16 secured to one of the poles of the magnet, and a similar pole piece assembly 17 secured to theopposite pole.

The pole piece assembly 16 has projecting pole pieces 18 and 19 defining between them a winding-receiving space. The pole piece assembly 17 is similarly provided with pole pieces 20 and 21 extending toward the pole pieces 18 and 19. 'A coil or winding is positioned within the winding-receiving space and may have. over it, if desired, a sheet of copper,26.- The armature 22' passes between the pole pieces 18' and20,'through the coil or winding 25 andbetween the pole pieces-19 and 21. and is preferably made substantially cylindrical, except where is passes betweenthe pole pieces 19: and 21, where it is madeyrelativelywide and thinner than a the opposite end.

-The pole pieces 18iand 20 are-separated by i a greater gap than-the pole pieces 19 and 21, 7

but are so arranged-as to leave only a very small space between them and the armature 22, whereas the pole pieces 19 and 21 are so arranged as, to leave aslightly greater space between them and the "armature lat-point 2 1.

The pole piece'assemblies 16 and 17 may, if

desired, be in the form of a plurality of laminations bolted'or. otherwise clamped together;

Y For the purpose of supporting the armae ture, there is provideda non-magnetic yoke 36 secured over the pole'pieces by means of bolts 28- and 29 and having ears 36a and 366,

which are turned downwardly'over the ends of the pole piece assembly. Aspring 30 of phosphor bronze or other suitablematerial is'se'cu'red-to the'ears 36a and 36bby means of suitable bolts'31 and 32, andthe spring is insulated from the yoke by means of insulating members 33, 34, and 38. A hole is provided in the spring 30, into which .the end'of armature 22, which is preferably tapered or provided with a portion 10f smaller diameterat'its end, may be inserted. A collar 37 may then be placed around-the extending portion, which isthen upset over the collar, as, for example, by hammering. The

armature is thus secured in position and is biased by the'actionof the spring '30 to neu tral position in the air gap.

j It will now be understood that by passing voicei currents'of a suitable value through the winding 25, the armature 22 is caused to vibrate in accordance withsuch currents.

For the purpose of inscribing such vibrations upon the record, there is provided a base ring 40 mounted belowthe plate 1. This, base ring is provided. at' one side with adownwardly extending; portion terminating nformed arms 41 and 42 carrying a suitable pivot 43 on which the floating support 4A is mounted.

The support 44 may comprise, forexample, a metal stamping having an upset edge and an internal domed portion 45; the upset edge of the support t tsecuresin position a disc of suitable insulating and damping material suchas bakelite. Attached to the floating su ort 44: there are provided a pair of arms @6 and 47, held together. by means of a bolt 48 and integral yoke 480, the extremities of which are providedwith tapered openings for receiving the tapered points of the shaft or pivot 43.

Mounted upon the disc 50 there are provided a pair of support blocks 51 and .52, which are secured only to the insulator'50 and not to the support 44c. Suitable bearingpivots 53 and 54:21'6 threaded through the blocks 51 and 52. The oscillating'lever 55 is provided with oppositely extending arms 56 and 57 ,provided at their extremities with tapered holes for receiving the tapered points of the bearings 53 and 54:,by means of which the lever 55 is allowed to rock. On one end of the lever 55 there is provided a cutting stylus, such as a jewel-58. A rigid link 59 is provided for connecting the other end of the lever 55 and the free end of the armature 22. The insulator50 and the support 14: areprovided with suitable openings to permitthe passage of said link. v

The link 59 is preferably made as light as possible consistent with suflicient rigidity, and for this purpose is substantially U shaped in cross section andprovided with extensions 60 and 61 at its lower end, arranged to embrace the end of lever 55, and a suitable rivet 65 is passed through the extensions 60 and 61 and the end of the lever 55. The link is; connected at its upper end to the armature through the medium of a block 66 pivotally secured in theend of the link, as shown in Figure 4, which block is provided with an extension 67 passed through a hole in the armature and soldered therein; .The connection of the link at each end is so arranged as to permit free rotation of the link on each pivot, but in a manner substantially to prevent any play or rattle.

The floating support permits the stylus to move up and down to accommodate itself to irregularities in the surface of the record while in motion, while at the same time the stylus is maintained in contact with the surface and caused to engrave the surface in accordance with the vibrations of the armature.

The insulating material interposed between the oscillating lever 55 and the floating support and the insulating material interposed between the armature assembly and the frame serve to elec-tricallyisolate the vibrating apparatus and minimize the effect of stray currents flowing through the frame of the machine due, for example, to the grounding of the electric motor used for driving the mechanical vibrations from being impressed upon the record. The damping function of thebakelite or otherinsulator serves also to minimize or prevent the establishment of parasitic resonance such as that due to the natural period of the armature and its support, which would distort the record and which resonanceI have found to cause a sharp and nasal quality in the record in case the insulator 50, for example, is omitted, and the vibrating lever mounted directly upon the floating support 44 or upon a disc of metal in place of the insulator 50.

The provision of the insulating and damping means around the armature supportlng spring serves the same purpose, as I have I foundthat without these insulators the recorded sounds are inclined to be somewhat sharp-and nasal. p, Under-certain conditions, if excessive amplitudes ofcurrent are used, it may be found that the end of the. armature 22 will strike the pole piece, giving rise to a rattle which is undesirable- Thismay be prevented, and resonance-which may be due to thenatural period ofthe armature itself andits spring support may be'further decreased by the interposition of suitable damping means between the armature 22 and the pole pieces 19 and 21; this damping material maybe in the form of paper folds 68,0r thin strips of rubher, or the like, inserted between the ar1nature and the pole pieces, asshown in Figure 1. Referring now more particularly to Figures 5, 6, 7 and v8, I have shown a device according to my invention more particularly adapted for use asa reprodu-cer and in which thesame reference numerals designate the same parts as 1n the prevlous figures, The magnetlc unit in thlscase is substantially the same as that shownin Figures 1 and 2.

The reproducing lever a, carrying stylus orjewel 58a,'is pivotally mounted onv shaft 56a upon the upper side ofthe floating support 44a. In this instance, shaft 56a passes through lugs 51a and 52a in groove on the upper side of floating support- 44:. The reproducing lever 55a is preferably made somewhat shorter than the recording lever 55, and 5.5

is mounted with its stylus toward the axis of the floatingv support, and the free end of the lever 55a is connected to the armature by link 59a. I

' For convenience in bringing up the leads the upperend of fibre striplla may be folded down as at 7 6 to provide room for-the leads to emerge if they are connected upon the inner side of the insulating member, and terminals not shown may be secured to strip 11a, to which terminals theleads may be connected.

The operation of this arrangement, it is believed, will be clear from what has already been said. The stylus or jewel 58a engages therecord and is vibrated thereby. The vibrations of the lever 55a are transmitted through link 59a to the armature, which is caused to vibrate in the air gap. The vibration of the armature varies the flux passing through coil 25 and causes the generation in that coil of an electromotive force which is closely proportional to the vibrations of the stylus. The floating support upon which the lever 55a is pivoted is allowed to move up and down due to irregularities in the thickness of the record, without substantially affecting the reproduction, as will be understood.

For thepurpose of preventing the floating support from swinging too far downwardly, an adjustable stop may be formed by a screw 77, which engages block 78 carried by the support. It is clear that by rotating the screw 77 in a direction to raise its lower end, the floating support is allowed to swing further downwardly, and, conversely, rotating the screw to lower its lower end decreases the point to which the floating support can drop.

'While I have shown and described certain preferred embodiments of myxinvention, it will be apparent that modifications and changes maybe made without departing from the spirit and scope of my invention, as will be understood by those skilled in the art.

I claim 2- v 1.- An electrical sound recorder comprising, in combination, a frame, a floating support pivotally mounted on said frame, a lever arm pivotally mounted for oscillation on said floating support, a stylus mounted on one end of said arm, a link pivotally secured to the other end of said arm, a magnetic driving motor mounted on said frameand comprising a Vibratile armature biased to neutral position, and electromagnetic means for positively actuating said armature in either direction, and a pivot connection between said motor positioned on said frame, said motor comprising a vibratile armature, spring biased to neutral position, and electromagnetic means for positively actuating said armature in either direction from neutral, a floating support pivotally secured to said frame, a lever mounted for oscillation thereon, a stylus mounted on one end of said lever, and a link pivotally connected on one end to the other end'of said lever, and on the other end to said armature. v

3. Anelectrical sound recorder comprising, in combination, a frame, a magnet support adjustably secured to said frame, a magnetic driving motor positioned on said frame, said motor comprising a vibratile armature, spring supporting said armature in neutralposition 'biased to neutral position, and electromagposition, a floating support pivotally secured I to said frame, a lever mounted for oscillation thereon, a stylus on one end of said lever, and a rigid link pivotally connected between one end of said armature and the end of said lever opposite said stylus, said link being so arranged as topositively drive said stylus in either direction of movement. i

4- An electrical sound recorder comprising, in combinatioma frame, amagnetic driving motor positioned on said frame, said motor comprising a vibratile armature, a spring for and insulating means interposed'between said spring and its seat, and electro-magnetm means forpositively actuating said armature in either direction from neutral position, a floating support pivotally secured to said frame, a lever'mounted for oscillation thereon, a stylus on one end .of saidlever, and'a rigid link pivotally connected between one end ofsaid armature and the endof said lever opposite saidstylus, said link being soarranged asto positively drive said stylus'ineither direction of movement. L 5. An electr cal sound recorder comprising,

in combination, a frame, a magnetic driving motor positioned on said frame, said motor comprising'a vibratile'armature, a spring for supporting said armature in neutral position,

and electro magnetic'means for positively actuatin'g said armature in either direction from neutral position, a floating support pivotally steamers said frame, an insulator mounted on saidsupport, a lever pivotally mounted for oscillation on said insulator, a stylus on one end o-f'said lever, and arigid link pivotally connected between one end of said armature and the end of said lever opposite said stylus,

said link being so arranged as to positively drive said stylus ineither direction of movement.

6. -An electrical sound recorder comprising, in combination, a frame, a magnetic driving motor positioned on said frame, said motor comprising a vibratile armature, a spring for supporting said armature in neutral position, insulating means interposed between said spring and its seat, and electro-magnetic means for positively actuating said armature in either direction from neutralposition, a floating sup-port pivotally secured to said frame, an insulator 'mountedon said support, a lever pivotally mounted for oscillation on said' insulator, a stylus on one end of said lever, and a rigid :link pivotally connected between one end of said armature and the end of said lever opposite said stylus, said link being-so arranged as'to positively drive said stylus in either direction of movement. I

7. An electrical sound recorder comprising, in combination, a frame, a magnetic driving motorpositioned on said frame, said motor "comprising a magnet having pole pieces expieces and interlinking saidwinding, a spring for supporting said armature in neutral position for oscillation, anddamping means interposed between saidarmature and said pole pieces at the point ofmaximum vibration amplitude of said armature.

8. An electrical sound recorder comprising, in combination, a frame, a floating support pivotally mounted on said frame, a lever arm pivotally mounted for oscillation on said floating support, a stylus mounted onone end of said arm, a link pivotally secured to the other end of said arm, a magnetic driving 'motor mounted on said'frame andcomprismg a vibratile' armature biased to neutral position,'a magnet having pole pieces defining a pair of air gaps at opposite ends of said armature, a coilsurroundingsaidf armature, and a pivot connection between saidlink and said armature in the plane ofsaid air gaps.

' 9. An electrical sound recorder comprisport pivotally mounted on'said frame, a lever floating support about an axisp'ara'llel to the axis of said support butoflset therefrom, a stylus mounted on the end of said lever arm remote from the axis of said support, a magnetic driving motor mounted on said :frame and comprising amagnet having a pair of pole piecesdefining an air gap, an armature of magnetic material mounted for vibration within said air gap, and a connection between said armature and the free. end of said lever arm. r a

10. An electrical sound reproducer comprising, in combination, a frame, a floating support pivotally mounted on said frame, a lever arm pivotally. mounted for oscillation ing, in combinatiomia frame, a floating supon said floating support,lastylus mounted on one end of said arm, and means for converting movements. of said stylus intov electrical currents, comprising a magnet having pole pieces defining a plurality of air gaps, an armature positioned within said gaps for vibration therein, a. coil surrounding said armature, and a connection between the free s end of said lever arm and said armature.

;11. An electrical sound reproducer comprising, in combination, a frame, a floating support pivotally mounted on said frame, a

lever arm pivotally mounted for oscillation on said floating support about an axis parallel to the axis of said support but offset therefrom, a stylus mounted on one end of said lever, and meansfor convertingmovements of said stylus into electrical currents, comprising a magnet having pole pieces defining a pair of airgaps, anarmature biased to neu-' tral position and mounted for vibration within said gaps, and a connection between the free end of said lever arm and said armature.

12. An electro-mechanical translating device comprising, in combination, a frame, a fioating support pivotally mounted on said frame, a lever arm pivotally mounted on said support for oscillation thereon, a stylus mounted on one end of said arm, a magnet mounted on said frame, pole pieces defining an air gap mounted on said magnet, an armature mounted for vibration in said gap and biased to neutral position, and a connection between said'lever and said armature.

13. An electro-mechanical translating device comprising, in combination, a frame, a floating support pivotally mounted below said frame, a lever arm pivotally mounted on said support for oscillation thereon, a stylus mounted on one end of said arm, a magnet mounted on said frame, pole pieces defining a pair of air gaps mounted on said magnet, an armature mounted for vibration in said air gaps, resilient damping means surrounding a portion of said armature, and a connection between said lever and said armature.

14. An electro-mechanical translating device comprising, in combination, a'frame, a floating support pivotally mounted below said frame, a lever arm pivotally mounted on said support for'oscillation thereon, a stylus mounted on one end of said arm, a magnet mounted on said frame, pole pieces defining a pair of air gaps mounted on said magnet, an armature mounted for vibration in said air gaps, resilient damping means surrounding a portion of said armature, and a connection between said lever and said armature at a point outside the portion thereof included between said air gaps.

40 This specification signed this 31st day of October, 1928.

CHARLES HUENLICH.

DISCLAIM ER 1,812,957 .Oharles Haenlich, Bloomfield, N. J. ELECTRICALLY OPERATING SOUND RECORDER AND REPRODUCER. Patent dated July 7, 1931. Disclaimer filed April 13, 1934, by the patentee, and the assignee, Thomas A. Edison, Incorporated.

Hereby enter this disclaimer to that part of the said specification which consists of claims numbered 7, 9, 10, 11, 12, 13, and 14, which respectively are in the following words, to wit:

7. An electrical sound recorder comprising, in combination, aframe, a magnetic driving motor positioned on said frame, said motor comprising a magnet having pole pieces extending toward each other, and each having projecting portions at each end defining a winding-receiving space, a winding therein, an armature positioned between said pole pieces and interlinking said winding, a spring for supporting said armature in neutral position for oscillation, and damping means interposed between said armature and said pole pieces at the point of maximum vibration amplitude of said armature.

9. An electrical sound recorder comprising, in combination, a frame, a floating support pivotally mounted on said frame, a lever arm pivotally mounted for oscillation on said floating support about an axis parallel to the axis of said support but offset therefrom, a stylus mounted on the end of said lever arm remote from the axis of said support, a magnetic driving motor mounted on said frame and comprising a magnet having a pair of pole pieces defining an air gap, an armature of magnetic material mounted for vibration within said air gap, and a connection between said armature and the free end of said lever arm.

10. An electrical sound reproducer comprising, in combination, a frame, a floating support pivotally mounted on said frame, a lever arm pivotally mounted for oscillation on said floating support, a stylus mounted on one end of said arm, and means for converting movements of said stylus into electrical currents, comprising a magnet having pole pieces defining a plurality of air gaps, an armature positioned within said gaps for vibration therein, a coil surrounding said armature, and a connection between the free end of said lever arm and said armature.

11. An electrical sound reproducer comprising, in combination, a frame, a floating support pivotally mounted on said frame, a lever arm pivotally mounted for oscillation on said floating support about an axis parallel to the axis of said support but offset therefrom, a stylus mounted on one end of said lever, and means for converting movements of said stylus into electrical currents, comprising a magnet having pole pieces defining a pair of air gaps, an armature biased to neutral position and mounted for; vibration within said gaps, and a connection between the free end of said lever arm and said armature.

12. An electro-mechanical translating device comprising, in combination, a frame, a floating support pivotally mounted on said frame, a lever arm pivotally mounted on said support for oscillation thereon, a stylus mounted on'one end of said arm, a magnet mounted on said frame, pole pieces defining an air gap mounted on said magnet, an armature mounted for vibration in said gap and biased to neutral position, and a connection between said lever and said armature.

13. An electro-mechanical translating device comprising, in combination, a frame, a floating support pivotally mounted below said frame, a lever arm pivotally mounted on said support for oscillation thereon, a stylus mounted on one end of said arm, a magnet mounted on said frame, pole pieces defining a pair of air gaps mounted on said magnet, an armature mounted for vibration in said air gaps, resilient damping means surrounding a portion of said armature, and a connection between said lever and said armature.

14. An electro-mechanical' translating device comprising, in combination, a frame, a floating support pivotally mounted below said frame, a lever arm pivotally mounted on said support for oscillation thereon, a stylus mounted on one end of said arm, a magnet mounted on said frame, pole pieces defining a pair of air gaps mounted on said magnet, an armature mounted for vibration in said air gaps, resilient damping means surrounding a portion of said armature, and a connection between said lever and said armature at a point outside the portion thereof included between said air gaps.

[Ofiicial Gazette May 8, 1934.] 

